assertions (version 0.1.0)

assert_reactive: Assert that x is reactive

Description

Assert that x is reactive

Usage

assert_reactive(x, msg = NULL, call = rlang::caller_env(), arg_name = NULL)

Value

invisible(TRUE) if x is a reactive, otherwise aborts with the error message specified by msg

Arguments

x

An object

msg

A character string containing the error message to display if x is not reactive

call

Only relevant when pooling assertions into multi-assertion helper functions. See cli_abort for details.

arg_name

Advanced use only. Name of the argument passed (default: NULL, will automatically extract arg_name).

Examples

try({
# Assert that a variable is reactive
x <- shiny::reactive(1)
assert_reactive(x)  # does nothing

# Assert that a variable is not a list
x <- 1
assert_reactive(x)  # stops execution and prints an error message
})